1. Field of the Invention
The invention refers to a package for the shipping and handling of lengths of optical fiber and in one aspect to a supply package for optical fiber jumpers including cable and connectors.
2. Description of Prior Art
Optical fibers are used extensively in the telecommunications and data transmission industry because they carry a vast amount of information. Typically the buffered fiber contains an 8 to 100 .mu.m central glass core through which the optical signal is transmitted. The glass core is surrounded by a glass cladding which has a diameter of up to 250 .mu.m. Usual cable, at least one additional plastic coating is applied over the cladding. The cladding has a slightly different index of refraction than the core. Therefore, to eliminate degradation it is important when handling the optical fiber that it is not kinked or wrapped about a radius less than the recommended minimum bending radius of the fiber.
Optical fiber connectors, of the type illustrated for example in U.S. Pat. Nos. 4,173,389, 4,458,985, 4,812,009 and 4,852,963, are placed on a length of optical fiber in a manufacturing environment such that the optical fiber core is centered and sealed in the connector and the end of the fiber core is polished. This length of optical fiber with a connector at each end forms a "jumper." When the length of fiber of a jumper is cut it forms two "pigtails." Each pigtail is adapted to have its free end spliced to the end of a fiber for connecting an incoming or distribution line to the connector. As a jumper, the assembly is adapted to connect two optical fiber devices.
The product to be packaged is thus the jumper or two pigtails for supplying the field technicians with parts for making the fiber installations. The jumpers are tested before leaving the manufacturing site and often it is desirous for the end user to test the connectors and length of cable received. It is tested by connecting the connectors to a test fixture which sends a light signal through the jumper to measure for any losses in signal.
Known packaging systems for lengths of fiber and for a length of optical fiber and the associated connector, or connectors, include such things as forming the fiber into a coil, binding it with cable ties or the like and placing it in a zipper bag.
Alternative packaging systems include a plastic sheet with a vacuum formed annular recess formed in one side of the sheet of clear plastic in which the coil of optical fiber is placed with the connector or connectors extending therefrom into recesses formed along the marginal edges of the sheet. The coil of fiber is retained by a soft resilient annular foam material formed to fit in the recess to retain the fiber. A cardboard cover then closes the back of the vacuum formed plastic sheet and the foam, and the cover and sheet are placed in a box. The latter package describes a package used by AT&T for pigtails for fiber optic systems.
Additionally, samples of optical fiber have been packaged in a folded paper file having generally circular halves joined about a fold line and one of the halves of the file has punched cut ears, comprising spaced holes and an arcuate cut joining the holes, arranged in a pattern to receive a length of sample fiber. A closing tab is also formed on the same half opposite the fold which fits into a slit in the other half of the file. The sample length of fiber is wrapped on the ears and the other half of the file forms a cover which folds over the fiber and is held in position by the tab. This is a package used currently by Corning Glass Works of Corning, N.Y. for samples of optical fiber.
The packages of the prior art do not afford a convenient way of supplying a jumper in a manner to be tested, or of supplying pigtails. The packages of the prior art did not permit equal lengths or predetermined measured lengths of fiber to be readily supplied with each connector.
The package of the present invention affords a package in which the length of optical fiber with mounted connectors is wrapped to protect the fiber. The package allows testing of the jumper prior to and after shipping without handling of the fiber. The package allows separation of the jumper to form a pair of pigtails. The pigtails can have an equal length of fiber connected to each connector or predetermined different lengths. One pigtail can be removed from the package without disturbing the other.